Hand-portable fire fighting, positive pressure blower

ABSTRACT

The drawings and description describe a hand-portable fire fighting, positive pressure blower 10 for providing positive pressure within a smoke filled space to remove the smoke, heat and carbon dioxide from a smoke filled space to facilitate the extinguishment of the fire and the overhauling of the space subsequent to the extinguishment. It further greatly enhances the safety of the fire fighters. The blower 10 includes a portable support frame 12 having an internal combustion engine 13 mounted thereon with a two blade wooden prop 18 mounted on the drive shaft for generating a cylindrical stream of fast moving air to be directed into the smoke filled space. The blower 10 includes a tilting mechanism 22 that has a lead screw with a crank that extends between a front leg frame section 58 and a central frame section 24. The front leg section 28 has a vibrational dampening cross frame element 60 that extends between the forward extending left front leg 62 and the right front leg 64. The supporting frame 12 includes a handle frame element 44 that substantially circumscribes the internal combustion 14 for protecting the engine from damage. As illustrated in FIG. 2, the unit when in the contracted position forms a very compact unit that may be readily mounted in a small compartment on a fire fighting vehicle.

TECHNICAL FIELD

This invention relates to fire fighting equipment and more particularlyto hand portable fire fighting, positive pressure blower classified inClass 169, subclass 99.

BACKGROUND OF THE INVENTION

It has been found that positive pressure ventilation of a structuresustaining an internal fire has many advantages. The use of positivepressure ventilation techniques usually results in removing the smoke ina fraction of the time previously required. The faster evacuation ofsmoke reduces smoke damage. Most importantly the rapid removal of thesmoke dramatically increases fire fighting safety. The firemen haveconsiderably greater visibility to see within the burning structure andto rapidly locate the hot spots without having to crawl on the floor.Also, the speedy removal of smoke and the replacement with cool freshair allows breathing apparatus to be removed sooner. Overall physicalstress of fire fighters is reduced with less stress related injuries.This all results in greater fire fighting productivity in being able toput the fire out more quickly. Furthermore, such a procedure causes lesssmoke and fire damage and increases fire fighter safety.

To be able to obtain the many advantages of positive pressureventilation, a lightweight, hand portable positive pressure blower isrequired that can be easily maneuvered into position in front of anopening to the structure. The blower must be sufficiently compact to beable to conveniently fit on a fire fighting vehicle without interferingwith other equipment. More particularly the blower need fit within arather compact compartment on the vehicle. In addition it is necessarythat the blower be able to direct a large volume of air in a ratherconfined directional air stream that is vertically adjustable.

Although there are a number of portable positive pressure blowerspresently on the market, they are generally difficult to store in asmall confined compartment on the fire engine. Furthermore such unitsgenerally, when in use, vibrate excessively and progressively changeposition. Consequently, it is not unusual for a fire fighter to eitherstand and hold the blower in place or to provide some type of hold downmechanism.

One of the objects and advantages of the present invention is to providea compact, hand portable positive pressure blower that can be easilystored on a fire fighting vehicle, particularly in a rather smallcompartment.

A further object of this invention is to provide such a blower in whichthe vibration of the blower is sufficiently dampened so that it will notmove when in full operation at its highest capacity.

An additional object of this invention is to provide such a blower thatmay be tilted at an infinite variation between zero and fifteen degreeswithout adversely affecting its stability.

These and other objects and advantages will become apparent upon readingthe following description of a preferred embodiment of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiment of the invention is illustrated in theaccompanying drawings, in which:

FIG. 1 is a perspective view of a preferred embodiment of thisinvention, illustrating a compact, hand-portable, positive pressureblower, particularly emphasizing the frame structure;

FIG. 2 is a side view of the blower illustrated in FIG. 1, illustratingthe blower at a zero inclination; and

FIG. 3 is a side elevation view similar to FIG. 2, except showing theblower at a fifteen degree inclination and the orientation of the frontlegs.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following disclosure of the invention is submitted in compliancewith the constitutional purpose of the Patent Laws "to promote theprogress of science and useful arts" (Article 1, Section 8).

Referring now in detail to the drawings, there is illustrated in FIG. 1,a hand-portable fire fighting, positive pressure blower generallydesignated with the numeral 10 for creating a rather high velocitystream of air for directing such stream of air into a smoke filled spaceof a burning structure for assisting the fire fighters in (1) puttingout the fire within the structure and (2) overhauling the structureafter the fire has been extinguished.

The blower 10 includes a portable support frame generally designatedwith the numeral 12 for supporting an internal combustion engine 14thereon. The internal combustion engine 14 has a drive shaft 16extending substantially horizontal therefrom. A propeller 18 is mountedon the drive shaft for rotating with the drive shaft to generate astream of high velocity air that is directed from the outside of a smokefilled space and driving or displacing the smoke from the space. Thepropeller 18 has a propeller guard 20 mounted about the propeller toprevent a fire fighter from being injured from the rotating propeller.

The blower 10 further includes a tilting mechanism 22 for tilting theinternal combustion engine 14 and propeller 18 in an infinitely variableangle between zero and 15 degrees to accurately adjust the elevationaldirection of the stream of outside air.

The portable support frame 12 includes a central frame section 24 thathas a left upright pillar frame element 26 and a right upright pillarframe element 28 that extend upward between the internal combustionengine 14 and the propeller 18. Each of the frame elements 26 and 28extend from lower ends 30 to upper ends 32. The central frame section 24includes transverse or cross base elements 34 and 36 that extendsubstantially parallel with each rigidly interconnecting the pillarframe elements 26 and 28. The transverse brace elements 24, 26 extendtransversely between the internal combustion engine 14 and the propeller18. The central frame section 24 includes engine mount frame elements 40that extend rearward from the cross brace element 36. The internalcombustion engine 14 is mounted to the engine mount frame elements 40 byengine mount bolts 42.

The central frame section 24 further includes the handle frame element44 that is substantially U-shaped with side rail sections 46 that areaffixed to the upper ends 32 of the pillar frame elements 26 and 28,respectively, and extend rearward along the side of the engine over theengine to a central rear rail 48. The handle frame element 44 ispreferably formed as a unitary part. Portable support frame 12 furtherincludes a rear leg frame section 50 that is preferably formed as aunitary U-shaped part having a horizontal portion 52 and rear legs 54extending downward and rearward at an inclined angle with respect to thecentral frame section 24.

All of the frame elements 26, 28, 34, 36, 40 and 48 are preferably madeof tubular metal or a composite material and are welded together to forma rigid frame structure. Rubber feet or mounts 56 are mounted to thelower end of the rear legs 54 for engaging a substantially horizontalsurface.

The portable support frame 12 further includes a front leg frame sectiongenerally designated with the numeral 58 that is likewise preferablyformed of a unitary U-shaped frame part consisting of a cross frameelement 60 and a left front leg 62 and a right front leg 64 that extendforward from the cross element 60. The front leg frame section 58 ispivotally mounted to the lower ends 30 of the pillar frame elements 26and 28 respectively at pivot locations 66. It is quite important thatthe cross frame elements 60 not be directly connected to the centralframe section 24 as the cross frame element 60 serves as a vibrationaldampening frame element for materially dampening the vibration caused bythe internal combustion engine 14 and the propeller 18. Furthermore thecross frame element 60 serves as a torsion bar between the left frontleg 62 and the right front leg 64 to further decrease the vibration andto cause torsional forces to be transferred from one front leg to theother front leg. Each of the front legs 62 and 64 have a forward portion68 that extends from the pivot point 66 to forward ends supported onrubber feet or pads 71. Additionally, each of the front legs 62 and 64has a rearward portion 70 that extends rearward from the pivot 66 to thecross frame element 60. Consequently, the forward portion 68 pivots upand down about the pivot 66 to raise and lower the front end of theblower 10 to tilt the frame between zero and 15 degrees.

The tilting mechanism 22 includes a screw bracket 72 welded to a lowerend 30 of one of the upright pillar frame elements 26, 28. The tiltingmember 22 includes a screw bracket 74 welded to a forward portion 68 ofone of the front legs 62, 64. A screw assembly 76 is operativelyinterconnected between the screw brackets 72 and 74. The screw assembly76 includes a screw bearing rotatably mounted at the screw bracket 72and a screw bearing mounted at the screw brackets 74. The screw bearingsreceive a lead screw 82 for providing an infinite adjustment of thedistance between the screw brackets 72 and 74 about the pivot axis 66 toprovide an infinitely variable adjustment of the tilted angle. A crank84 is mounted to the screw 82 for manually turning the screw 82 toadjust the inclination. In FIG. 2 the screw is turned to position theblower at the zero or contracted orientation with the drive shaft 16being substantially parallel with the supporting horizontal surface.FIG. 3 shows the screw 82 having been rotated a certain degree to adjustor pivot the front legs 62 and 64 downwardly to position the shaft 16 atan angle approximately 15 degrees to horizontal to direct the highvelocity air stream at an upward angle.

The rubber feet or pads 56 and 71 are formed of a rather soft rubbermaterial of between 30-40 durometer to additionally assist in absorbingthe vibration of the blower and to provide good frictional contactbetween the legs of the blower and the horizontal surface. It has beenfound that the unit, particularly because of the cross frame element 60,absorbs most of the vibration and that the unit will stay stationaryeven though the engine is operated at its maximum speed. Thus a firefighter is not required to stand at the unit to hold the unit in placeduring operation.

The propeller 18 is preferably constructed of a wood material having twoopposing blades 86 and 88 that extend radially outward on opposite sidesof a hub 90. The hub 90 is mounted on the shaft 16 by direct connection.There is no speed reduction between the drive shaft and the propeller.The applicant has found that a solid wood propeller has many advantagesover other propellers when operating at rather high speeds.

The propeller guard 20 is mounted about the propeller 18 utilizing guardmounting clamps 92 that are illustrated in FIG. 1.

It should be noted that when the blower is in a contracted position asillustrated in FIG. 2 in which the frame elements extend just a slightdistance beyond the engine and propeller assembly to provide a verycompact unit. The upper handle structure protects the engine from damageshould the unit be tipped over. It should be noted that the front legs62 and 64 extend underneath the propeller at a very close distance toprovide maximum support while providing a very compact unit that can beeasily stored in a rather small compartment in a fire fighting vehicle.

It should be noted the propeller is shroudless. The propeller 18 withthe two oppositely directed blades formed of wood which provide asufficiently confined stream of air that is very directional in nature.Many of the prior art devices utilize a shroud about the propeller withmultiple fan blades in an attempt to confine and direct a cylinder offast moving air towards the opening of the smoke filled space. Theapplicants' design does not require such a shroud.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural features. It is to beunderstood, however, that the invention is not limited to the specificfeatures shown, since the means and construction herein disclosedcomprise a preferred form of putting the invention into effect. Theinvention is, therefore, claimed in any of its forms of modificationswithin the proper scope of the appended claims appropriately interpretedin accordance with the doctrine of equivalents.

We claim:
 1. A hand-portable fire fighting, positive pressure blower,normally stored on a fire fighting vehicle, that may be easily removedfrom the vehicle and used for removing smoke from a smoke filled spaceof a structure, comprising:a portable support frame for supporting theblower on a substantially horizontal surface adjacent an opening to thesmoke filled space; an internal combustion engine mounted on the framefor rotating a propeller drive shaft; a propeller operatively connectedto the drive shaft for directing a stream of outside air through theopening and into the smoke filled space to create a positive airpressure within the space to displace the smoke with the outside air; apropeller guard mounted on the frame surrounding the propeller; saidportable support frame having;(1) a central frame section receiving theinternal combustion engine and having central frame pillar elementsextending downward between the internal combustion engine and thepropeller to lower ends; (2) a rear leg section operatively connected tothe central frame section for engaging the horizontal surface rearwardof the internal combustion engine; (3) a U-shaped front leg sectionhaving two laterally spaced front legs and a vibration dampeningtransverse frame element in which the section is pivotally mounted tothe lower ends of the pillar elements for pivotal movement about atransverse axis with the spaced front legs extending (a) forward fromthe transverse axis underneath the propeller guard terminating insurface engaging feet forward of the propeller, and (b) rearward fromthe transverse axis to the vibration dampening transverse frame elementwith the transverse frame element serving as a vibration absorbingcomponent to prevent the blower from moving on the horizontal surfacedue to vibration of the internal combustion engine; and manual tiltingmeans operatively interconnecting the central frame section and theU-shaped front leg section for pivoting the central frame section aboutthe transverse axis to adjust the inclination of the spaced front legsand in response thereto to adjust the elevational direction of the airstream through the structure opening.
 2. The hand-portable firefighting, positive pressure blower as defined in claim 1 wherein themanual tilting means is operatively connected between the central framesection and the pair of front legs for infinitely adjusting theinclination of the front legs between a compact horizontal orientationand an expanded tilted orientation with respect to the horizontalsurface to enable fire fighters to adjust the angle of the outside airstream.
 3. The hand-portable fire fighting, positive pressure blower asdefined in claim 1 wherein the surface engaging front feet are made ofvibration dampening material.
 4. The hand-portable fire fighting,positive pressure blower as defined in claim 1 wherein the front legsand the vibration dampening frame element are formed of an integralU-shaped member.
 5. The hand-portable fire fighting, positive pressureblower as defined in claim 1 wherein the tilting means includes a firstscrew mounting bracket affixed to the central frame section and a secondscrew mounting bracket affixed to one of the front legs and a drivescrew extending between the first and second screw mounting brackets forpivoting the one front leg relative to the central frame section fortilting the blower in response to the movement of the drive screw. 6.The hand-portable fire fighting, positive pressure blower as defined inclaim 1 wherein the propeller has only two opposing blades formed ofwood.
 7. The hand-portable fire fighting, positive pressure blower asdefined in claim 1 where the central frame section includes (1) twopillar frame elements extending downward to the front legs sectionbetween the internal combustion engine and the propeller, (2) transversebrace frame elements extending between the two pillar frame elementsbetween the internal combustion engine and the propeller, and (3) ahandle frame element affixed to the two pillar frame elements andextending rearward over the internal combustion engine to facilitatemanual manipulation of the blower.
 8. The hand-portable fire fighting,positive pressure blower as defined in claim 3 wherein the vibrationdampening feet are made of a rubber material having a hardness ofbetween 30 and 40 durometer.
 9. The hand-portable fire fighting,positive pressure blower as defined in claim 1 wherein the supportingframe is constructed of square tubular metal material.
 10. Thehand-portable fire fighting, positive pressure blower as defined inclaim 1 wherein the rear leg extends downward and rearward from thecentral frame section at an inclined angle.